Big Idea: Negative numbers help us to model many real world situations.
Essential Question: How do I find the difference between integers?
3.2 & Follow-up
A)Use the number line to find each difference. Use a chipboard to check your work.
1) +7-+9= -2
2) -7-+9= -16
3) +7- -9= 16
4) -7- -9= 2 B)Use a number line to find each sum or difference.
1) +12-+3= 8
2 +12+-3= 15
3)-10--7=-17 4)-10++7= -17
C) Find the difference between each pair of numbers on a number line. In each case, tell how the distance is related to the difference is related to the difference between the two numbers.
1) 1 and 5 positive numbers are always on the right so we 4 spaces to the right.
2) -1 and 5 are both positive and negative numbers so we move on both sides of the number line, but because 5 is a larger amount of quantity the it will land on the right and you will move 6 spaces.
3)-5 and -9 are both are both negative numbers, so we stay on on the left side of the number line, we move 4 spaces so the answer should on the left side of 0.
4) -3 and 3 are both negative and positive numbers, so we go on both sides of the number line, 3+3= 6, so we move 6 spaces.
F.U.
When you add two positive integers you get a positive sum . When you subtract two positive integers, do you always get a positive difference? Explain.
No you can't get a negative number if you subtract a greater number from a smaller number, because if your subtracting more from a number than it is you go below 0 which is negative.
When you use the number line model, you can think of theabsolute valueof a number as its distance from 0. For example, 3 and -3 are each 3 units from 0, so the absolute value of each number is 3.
Use a number line to help you find a pair of numbers with the given absolute value.
10- 10, -10
5- 5, -5
1- 1, -1
7- 7, -7
10/4/09
Big Idea: Negative numbers help us to model many real world situations.
Essential Question: How do I find the difference between integers?
3.2 & Follow-up
A)Use the number line to find each difference. Use a chipboard to check your work.1) +7-+9= -2
2) -7-+9= -16
3) +7- -9= 16
4) -7- -9= 2
B)Use a number line to find each sum or difference.
1) +12-+3= 8
2 +12+-3= 15
3)-10--7=-17
4)-10++7= -17
C) Find the difference between each pair of numbers on a number line. In each case, tell how the distance is related to the difference is related to the difference between the two numbers.
1) 1 and 5 positive numbers are always on the right so we 4 spaces to the right.
2) -1 and 5 are both positive and negative numbers so we move on both sides of the number line, but because 5 is a larger amount of quantity the it will land on the right and you will move 6 spaces.
3)-5 and -9 are both are both negative numbers, so we stay on on the left side of the number line, we move 4 spaces so the answer should on the left side of 0.
4) -3 and 3 are both negative and positive numbers, so we go on both sides of the number line, 3+3= 6, so we move 6 spaces.
F.U.
- When you add two positive integers you get a positive sum . When you subtract two positive integers, do you always get a positive difference? Explain.
No you can't get a negative number if you subtract a greater number from a smaller number, because if your subtracting more from a number than it is you go below 0 which is negative.
Use a number line to help you find a pair of numbers with the given absolute value.When you use the number line model, you can think of the absolute value of a number as its distance from 0. For example, 3 and -3 are each 3 units from 0, so the absolute value of each number is 3.
10- 10, -10
5- 5, -5
1- 1, -1
7- 7, -7